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In March, correspondent Tom Bearden reported on the start of ten days of man made flooding of the Colorado river in the Grand Canyon, an effort to help return the river to it's natural, pre-dam, state. He returns to the site of that first report to update us on the results.
TOM BEARDEN: For 10 days in March, the floodgates at the Glen Canyon dam blasted 45,000 cubic feet of water every second into the Colorado River. The surge was designed to mimic the annual spring flooding that used to occur before the dam was built. The goal was to restore the ecosystem in the Grand Canyon 75 miles downstream which had been damaged by 23 years of dam operation. Backwater wildlife habitats in side channels had silted up and become overgrown, while sand bars had been eroded. The hypothesis was that the artificial flood would scoop up sand from the bottom of the river and deposit it on shore, rebuilding the beaches. It was also supposed to scour out the backwaters, restoring spawning grounds for threatened species of fish, like the humpback chub. The Bureau of Reclamation closed the huge valves on April 2nd. Nine days later, Interior Secretary Bruce Babbitt held a news conference.
BRUCE BABBITT, Interior Secretary: The flood is over; the waters have receded; and the beaches in the riparian zone has now reemerged for our inspection, and what we have found is really quite extraordinary. The success of this experiment exceeds, I think, the most optimistic hopes of our staff, the scientists, and all of the participants.
TOM BEARDEN: Grand Canyon National Park superintendent Robert Arnberger was equally enthusiastic.
ROBERT ARNBERGER, Superintendent, Grand Canyon National Park: The experiment has been successful, wildly successful. This is the payoff, the payback to the American people for a science well done, for a hypothesis played out, for the, the achievement of some notable restoration of the ecosystem along the river. Some of the early results are telling us quite clearly that there's been as much as a third or 33 percent gain in some of the, the sediment deposition on the sides, more sand bars. There's been some rejuvenation of backwater areas, including the creation of new backwater areas. Rejuvenation is extremely important because the backwater area can go dead if it doesn't have new, new nutrients coming in.
TOM BEARDEN: But some scientists are a bit uncomfortable with their bosses declaring success quite so quickly. Scientific teams were still on the river the day Sec. Babbitt held his news conference, and others have since returned for follow-up studies. The final scientific reports aren't even due until December. The last team came off the river April 12th. They loaded their equipment and samples onto trucks and prepared to return to Northern Arizona University in Flagstaff to begin the evaluation process. They had just traveled more than 200 miles downstream from Lees Ferry, which is just South of the dam. Jeff Bennett is an organic chemist, who is studying the presence of nutrients in sediment. That's the first link in the food chain that sustains backwater spawning.
JEFF BENNETT, Chemist: A lot of my numbers that come out in the field don't make necessarily a whole lot of sense until I can sit down and plot those out and, and look at 'em closely.
TOM BEARDEN: Two days later Bennett was back on campus beginning to look at his soil and water samples.
JEFF BENNETT: We took sediment samples before and after the flood, both from soil pits that we dug and from coring, with a coring device from the bottoms of those soil pits. The flood should have mixed some of these sediments around, and hopefully we'll see some changes in nutrient content and organic matter content and possibly in grain size also.
TOM BEARDEN: Geologist Joe Hazel was with Bennett on the river surveying the new sand bars. He'll plug his data into a computer system to assess how the flood changed the beaches.
JOE HAZEL, Geologist: Each one of these boxes is one of our study sites, and they're spaced throughout the entire length of the river, at least down to Diamond Creek, which is 225 miles downstream from Lees Ferry. Lees Ferry is 15 miles downstream from the dam.
TOM BEARDEN: But a more detailed analysis will have to wait, because the next day, Hazel was back at Lees Ferry, preparing to cast off for yet another 225-mile trip down the Colorado to take still more measurements. Lees Ferry also happens to be the launch point for tens of thousands of fishermen who come here from as far away as Asia to try their luck in the manmade Gold Medal Trout Fishery in Glen Canyon just below the dam. Dozens of guides, like Rick Smith, make their living taking people fishing.
RICK SMITH, Fishing Guide: (fishing from boat) There it is. Good one too.
TOM BEARDEN: Before the flood began, he was afraid the experiment would sweep the river bottom clean of algae, called cladofera, and the tiny shrimp that live on it. Those shrimp are the trout's main food supply.
RICK SMITH: I think everything that I've seen so far is pretty favorable. There's still some algae left, and, uh, this time of year is when the sun is more direct on the water, and I think a lot of it'll grow back. There's an abundance of fish, and, uh, and fish of all sizes, so that's really encouraging.
TOM BEARDEN: Clive Pinnock has been inspecting the river closely. He's a wildlife biologist in Glen Canyon National Park. He's more pessimistic.
CLIVE PINNOCK, National Park Service: I have major concerns about the trout fishery. There were many places, umm, that were scoured. Uh, there's no cladofera left in many places. As a matter of fact, a day right after the flood, we went, uh, and went upstream and looked at a lot of the beaches, and, uh, way up on the beaches, what's called a strand line, uh, were just carcasses of scuds, the tiny shrimp that live on the algae that basically supports this aquatic ecosystem.
TERRY GUNN, Fishing Guide: We suffered irreparable loss up river.
TOM BEARDEN: Fishing guide Terry Gunn thinks Glen Canyon suffered for no good reason.
TERRY GUNN: It's my belief and the belief of a lot of other people that this study was created by the scientists for the scientists to create jobs for the scientists into the next century.
ROBERT ARNBERGER: That's an unfortunate, cynical view of it all, and, and I guess I choose not to try to debate or try to convince those people because I'm not sure they can be convinced.
TOM BEARDEN: Going into the experiment, government press releases indicated scientists knew 95 percent of what would happen in advance, that the experiment would verify the other 5 percent. If so, there were some surprises in that 5 percent. Some $60,000 worth of equipment wound up under 15 feet of sand because the river unexpectedly undercut a test site and then buried it. And some of the nearly 200 rare amber snails that scientists had laboriously moved to higher ground ended up being eaten by mice. Nature may have one more surprise for the scientists. The snow pack in the Rocky Mountains is 150 percent of normal. When it melts, it will send a new surge of river down the Colorado into Lake Powell, behind the Glen Canyon dam. It could force another major release of water, which might erode some of the experiment's new beaches right back into the channel.
ROBERT ARNBERGER: I think that all of us are quite concerned that if there is a release, it depends on the size of the release and so forth, that in fact, the experiment results could be skewed or impacted in some way.
TOM BEARDEN: David Wegner manages the Glen Canyon Environmental Studies Group, the agency overseeing the entire experiment. He's been working on the project for some 13 years, negotiating between often hostile federal and state agencies. He says the results are worth the endless meetings and the $100 million in scientific studies it took to finally stage the grand flood of the Grand Canyon.
DAVID WEGNER, Glen Canyon Environmental Studies: I look at that investment as time and money well spent because now we have a network of water users, electrical users, scientists, technical folks, cultural resource, and native American people that are working together for a common cause, which is those, those resources in the Grand Canyon.
TOM BEARDEN: Wegner says the experiment has shown that the Glen Canyon Dam can be operated not only to store water and make electricity for big cities but also to repair the damage it's done to one of the world's greatest natural wonders. And if the evidence ultimately supports that claim, what is learned here will be applied to other dams all over the world.
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